Jan 6 (Reuters) - U.S. President-elect Donald Trump's donor Omeed Malik's blank-check firm will merge with GrabAGun, an online retailer of firearms, ammunition and gun accessories, in a deal valued at $150 million, the companies said on Monday.

Trump's son Donald Trump Jr., newly appointed adviser to GrabAGun, will become a shareholder after the company's deal with Colombier Acquisition Corp. II CLBR.N closes in the summer.

The merger will make GrabAGun one of several conservative-leaning companies that have entered the stock market in recent years, at a time when political pressure has prompted a reevaluation of socially conscious investing.

Truth Social-parent Trump Media & Technology DJT.O, lender Chain Bridge Bancorp CBNA.N and video-sharing platform Rumble RUM.O are among the conservative-focused companies which have gone public in the last few years.

"Much like Truth Social, PublicSquare and Rumble have led the charge to protect the First Amendment, GrabAGun will do the same for the Second Amendment," Trump Jr. said in a statement, referring to U.S. constitutional protections for free speech and the right to bear arms.

Malik, a former Democrat who was also a managing director at Bank of America Merrill Lynch BAC.N for six years, is part of a group of rich tech investors who have shifted right and embraced Trump in recent years.

He helped secure former independent presidential candidate Robert F. Kennedy Jr.'s endorsement for Trump after Kennedy dropped out of the race in August.

GrabAGun's shares are expected to trade on the New York Stock Exchange under the "PEW" symbol.

Founded in 2010, the company offers an assortment of sporting firearms, ammunition and accessories. It expects to benefit from a shift to online shopping by younger firearm enthusiasts, it said.

A blank-check firm, also known as a special purpose acquisition company, offers a way for private companies to list without the delays associated with a traditional initial public offering.

(Reporting by Jaiveer Singh Shekhawat and Niket Nishant in Bengaluru; Editing by Pooja Desai)

((JaiveerSingh.Shekhawat@thomsonreuters.com;))