In early afternoon trade, the S&P/ASX 200 Index (ASX: XJO) is on track to end the week with a solid gain. At the time of writing, the benchmark index is up 0.5% to 8,538.5 points.

Four ASX shares that are rising more than most today are listed below. Here's why they are pushing higher:

Lendlease Group (ASX: LLC)

The Lendlease share price is up 2% to $6.50. Investors have been buying this international property and infrastructure company's shares after it announced a deal to sell its Capella Capital business for a consideration of $235 million to Japanese trading company Sojitz Corporation. Management notes that this brings its total capital recycling transactions to $2.2 billion. Lendlease also revealed that the $516 million sale of its US Military Housing business to Guggenheim Partners has completed following satisfaction of all conditions.

Mesoblast Ltd (ASX: MSB)

The Mesoblast share price is up over 2% to $3.13. This follows the release of its quarterly result and an update on commercial activities. In respect to the latter, the launch of its Ryoncil product is planned for this quarter once it receives National Drug Codes (NDC) from the US FDA. Management estimates that steroid-refractory acute graft-versus-host disease (SR-aGvHD) is a US$1 billion annual market opportunity. Chief executive, Dr. Silviu Itescu, said: "We are committed to making our FDA approved product Ryoncil available as quickly as possible to the many children with SR-aGVHD in need of life-saving therapy. The team has been working relentlessly on finalizing product availability, including logistics, regulatory documentation, and contractual arrangements to ensure a successful launch of Ryoncil this quarter."

St Barbara Ltd (ASX: SBM)

The St Barbara share price is up 5% to 25.2 cents. This follows a strong rise in the gold price overnight and the release of the gold miner's quarterly update. St Barbara revealed that second quarter gold production was 10,262 ounces, which fell short of the anticipated production range or 14,000 to 16,000 ounces. However, stronger production is expected in the second half due to higher grade ore, installation of the sizer, new excavators, and truck fleet availability.

Zip Co Ltd (ASX: ZIP)

The Zip Co share price is up 2% to $2.49. This appears to have been driven by a broker note out of Citi this morning. In response to a post-quarterly update selloff on Thursday, the broker has upgraded this buy now pay later provider's shares to a buy rating with a $3.00 price target. While Citi has trimmed its estimates to reflect softer growth, its analysts believe the selloff was overdone and created a buying opportunity for investors.