"merger into" is correct and usable in written English.
You can use it when referring to two entities combining together to become one. For example, "The two companies merged into one larger organization."
Tells about the merger into the Malaysian Federation which only lasted a couple of years.
BA and Iberia completed their merger into International Airlines Group, I.A.G., in January.
In July, it and the Fraud Squad announced their merger into the Merchant Risk Council.
He joined Ramo-Wooldridge Corp. and remained there through a merger into what was to become TRW.
He became a vice president of the university and helped manage its merger into Case Western Reserve.
Pulling a fast one on BoS chief Peter Burt - by turning a merger into a takeover - was also naive.
CUC, formerly Comp-U-Card International, went public in 1983 and grew through mergers into the giant Cendant Corporation.
Although he started off with a small railway company in the 1920s, he gradually built this up through a string of takeovers and mergers into a sprawling conglomerate.
After graduating she turned her 500-page dissertation on the things needed for successful hospital mergers into a book called "Lessons from Mergers: Voices of Experience," which will be published next year (Health Administration Press).
Ebbers is accused of multiple accounts of fraud in connection with his promotion of WorldCom, the company he built through a series of mergers into a powerhouse that was once worth more that $150 billion.
But some companies recently ditched at the altar are preparing to drag their runaway merger partners into court.
