After confirming Friday its $375 million offer  to acquire the outstanding shares of Scottish life sciences company Axis-Shield Plc, Waltham-based Alere Inc. announced today that it has increased its ownership stake of the company's shares from 2.23 percent to 6.4 percent.
Alere (NYSE: ALR), a health-care management company, now owns about 3.2 million shares of Axis-Shield stock.
Axis-Shield develops compact portable analyzers and blood and fluid tests used in the analyzers.
Alere's confirmation of its offer on Friday followed a Bloomberg report issued a month earlier, stating that Alere had offered $369 million  for Axis-Shield, which had rejected the offer.
Alere focuses its diagnostics and monitoring technology in the areas of infectious diseases, cardiology, oncology, women's health and drug abuse. The company changed its name from Inverness Medical in May of 2010, stemming from the 2007 acquisition  by Inverness of Alere Medical Inc., of Reno, Nev., for $302 million in cash and stock.