Despite a recent deal to broaden its smartphone business, Lenovo Group (LNVGY) shares plunged more than 12% in Tuesday morning over-the-counter trading after a number of brokerages cut their ratings for LNVGY stock.

Morgan Stanley (MS), Jeffries Group, UBS (UBS), Kim Eng Securities and JI-Asia Research all downgraded LNVGY stock. A Morgan Stanley analyst cited the recent acquisition of handset-maker Motorola Mobility from Google (GOOG) by LNVGY, noting that LNVGY would have to spend time and money to turnaround Motorola’s struggling business, Bloomberg noted.

Last month, LNVGY agreed to pay $2.9 billion to acquire Motorola from Google. The Internet search engine giant had itself purchased Motorola for $12.5 billion in 2012.

LNVGY spent about $5 billion in on acquisitions in January. Aside from purchasing Motorola, LNVGY announced a deal to buy IBM’s (IBM) x86 corporate server business.

Prior to Tuesday, LNVGY stock had gained more than 20% over the past year. LNVGY stock closed at $25.39 on Monday.