UPDATE 1-Japan's FamilyMart to buy am/pm for $133 mln

* Deal makes am/pm wholly owned, closes gap with No.2 Lawson

* Says deal to have no impact on FamilyMart's annual outlook (Adds details, share price)

TOKYO Nov 13 (Reuters) - FamilyMart Co (8028.T), Japan's No.3 convenience store operator, said it would buy smaller rival am/pm Japan Co for 12 billion yen ($133 million) as it seeks growth in a saturated domestic market.

The move, to be completed next spring, will make am/pm a wholly owned subsidiary and help FamilyMart close the gap with Japan's No.2 convenience store chain Lawson (2651.T). [ID:nBNG460546]

FamilyMart will buy am/pm from Rex Holdings, which is owned 92 percent by Japanese private equity firm Advantage Partners. Advantage has been seeking a buyer for am/pm. [ID:nT20934]

am/pm has about 1,100 stores and FamilyMart, which also has sizable overseas operations, runs about 7,600 stores in Japan. Lawson has about 9,600 stores in Japan.

FamilyMart said in a release that the deal would have no impact on its annual earnings outlook, in line with market estimates according to analysts polled by Thomson Reuters I/B/E/S.

FamilyMart President Junji Ueda has said any acquisition of another chain is unlikely to work unless it can put all stores under the FamilyMart brand. The two are scheduled to hold a news conference at 0730 GMT.

After the news, which was well-flagged by media, shares of FamilyMart were up 2 percent, while Lawson was up 1.8 percent. (Editing by Chris Gallagher)