  We present a stochastic dynamics model of coupled evolution for the binary
states of nodes and links in a complex network. In the context of opinion
formation node states represent two possible opinions and link states a
positive or negative relation. Dynamics proceeds via node and link state update
towards pairwise satisfactory relations in which nodes in the same state are
connected by positive links or nodes in different states are connected by
negative links. By a mean-field rate equations analysis and Monte Carlo
simulations in random networks we find an absorbing phase transition from a
dynamically active phase to an absorbing phase. The transition occurs for a
critical value of the relative time scale for node and link state updates. In
the absorbing phase the order parameter, measuring global order, approaches
exponentially the final frozen configuration. Finite size effects are such that
in the absorbing phase the final configuration is reached in a characteristic
time that scales logarithmically with system size, while in the active phase,
finite-size fluctuation take the system to a frozen configuration in a
characteristic time that grows exponentially with system size. There is also a
finite-size topological transition associated with group splitting in the
network of these final frozen configurations.

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