Plenty of Aussie investors may have a significant allocation to Westpac Banking Corp (ASX: WBC) shares or other ASX bank shares in their portfolios. If that's the case, I think it could be a good idea to increase a portfolio's diversification to other ASX blue-chip shares.

Westpac is a great business, but a large portion of its earnings comes from its mortgage loan book, which is a big bet on the Australian housing market. Considering an ASX bank share-owning investor may also own their own home, owning a lot of Westpac shares could seem like a significant concentration risk on the property market.

With that in mind, I'm going to talk about two ASX blue-chip shares from different sectors that investors may wish to add to their portfolios instead of more Westpac shares.

Telstra Group Ltd (ASX: TLS)

Telstra is Australia's leading telecommunications business, with its market-leading position, the largest mobile network, and the strongest spectrum assets. In my view, it's an appealing ASX blue-chip share.

In the banking sector, Westpac shareowners must understand that the mortgage and deposit sectors are very competitive, with all the players offering similar loan and deposit products. Telstra's market-leading position allows it to retain and win customers even when it charges a higher price.

Telstra has increased prices for its customers over the last couple of years, enabling higher profit margins. The combination of new customers and a higher average revenue per user (ARPU) is a wonderful one, and it is one of the main reasons UBS is predicting Telstra's net profit after tax (NPAT) can rise by approximately 50% between FY25 and FY29.

With Australia becoming increasingly digital and connected, I believe this ASX blue-chip share is an appealing one to own for the foreseeable future.

Another reason to love Telstra shares is that they're a great dividend option. The payout has been growing in the last few years, and UBS expects the annual dividend per share to increase to 19 cents in FY25. That currently translates into a grossed-up dividend yield of approximately 7%. UBS expects the dividend to rise by approximately 50% between FY25 and FY29.

Breville Group Ltd (ASX: BRG)

Breville sells appliances, particularly coffee machines, through a variety of brands. It also has a growing coffee business called Beanz.

One of the main reasons I like Breville is that it's achieving international growth, whereas Westpac is just focused on Australia (and New Zealand). Expanding across the world gives the business a much larger growth runway.

In the FY25 half-year result, Breville reported that its revenue rose by 19.1% to $997.5 million, and net profit after tax (NPAT) increased by 16.1% to $97.5 million.

As noted by UBS, one of the most exciting bits of news from the result was that the ASX blue-chip share is expanding into the Middle East and China, which are two compelling markets for the company.

While the business isn't cheap, I'd suggest that Westpac shares aren't cheap either. I'd rather buy a globally growing business where earnings could continue climbing at a decent pace for years into the future.

According to the forecast from UBS, Breville is trading at 40x FY25's estimated earnings, and it is projected to grow its profit by 67% between FY25 and FY29.

In five years, I think Breville could be a significantly larger business, and it could be worth owning a piece of it during that journey.